Photocatalytic, structural and optical properties of mixed anion solid solutions Ba₃Sc₂₋ₓInₓO₅Cu₂S₂ and Ba₃In₂O₅Cu₂S₂₋ySey

Nine members of two contiguous solid solutions, Ba3Sc2−xInxO5Cu2S2 and Ba3In2O5Cu2S2−ySey (x, y = 0, 0.5, 1, 1.5 and 2), were synthesised at temperatures between 800 °C and 900 °C by stoichiometric combination of binary precursors. Their structures were determined by Rietveld refinement of X-ray powder diffraction data and found to adopt the SmNi3Ge3 structure with I4/mmm symmetry. Approximate Vegard law relationships were found within each solution between the lattice parameters and composition, with an observed cell volume of 466.4 Å3 for Ba3Sc2O5Cu2S2 increasing to 481.0 Å3 for Ba3In2O5Cu2S2 and finally to 499.0 Å3 for Ba3In2O5Cu2Se2. In the first solid solution, this volume increase is driven by the replacement of scandium by the larger indium ion, generating increased strain in the copper chalcogenide layer. In the second solution the substitution into the structure of the larger selenium drives further volume expansion, while relieving the strain in the copper chalcogenide layer. Band gaps were estimated from reflectance spectroscopy and these were determined to be 3.3 eV, 1.8 eV, and 1.3 eV for the three end members Ba3Sc2O5Cu2S2, Ba3In2O5Cu2S2, and Ba3Sc2In2O5Cu2Se2, respectively. For the intermediate compositions a linear relationship between band gap size and composition was observed, driven in the first solution by the introduction of the more electronegative indium lowering the conduction band minimum and in the second solution by the substitution of the electropositive selenium raising the valance band maximum. Photocatalytic activity was observed in all samples under solar simulated light, based on a dye degradation test, with the exception of Ba3In2O5Cu2Se1.5S0.5. The most active sample was found to be Ba3Sc2O5Cu2S2, the material with the largest band gap

Maximum loss acceptable to risk investment in brazilian commodity.

O presente trabalho teve como objetivo simular a perda m?xima aceit?vel para o risco de investimento em uma das principais commoditiesagr?colas do Brasil, o trigo. Para o cumprimento de tal objetivo, o estudo usou a modelagem de s?ries temporais com processos autorregressivos dem?dias m?veis (Arma), heterocedasticidade condicional (Garch) e valor em risco (V@R), aplicados sobre uma s?rie hist?rica de prec?os do ativonum intervalo de dez anos. O banco de dados investigado foi coletado no site do Cepea/Esalq/USP e a motivac??o para escolha dessa s?rie hist?ricase deu em func??o da import?ncia produtiva e econ?mica do Estado do Paran? para todo o Brasil, porque ? o maior produtor e comerciante dacommodity. Os resultados discutidos neste paper revelam que a um n?vel de signific?ncia estat?stica de 1%, o produtor de trigo admite uma perdade R$228,40 sobre o investimento feito e, a 5$ 174,19. Em geral, essas informac??es sugerem que a cada tonelada de trigo vendida, o produtorpode perder em seu investimento at? R$228,40. Estas e outras informac??es abordadas na pesquisa podem servir de ferramentas estrat?gicas deapoio para o processo decis?rio de investimento em commodities. A din?mica dos prec?os expressa pela volatilidade do mercado pode revelaralgum padr?o de comportamento do ativo, o que pode ser ?til para a formac??o de pol?ticas hedge, nas quais v?rios produtores assumem o risco doinvestimento efetivado, minorando assim o impacto do mesmo sobre os produtores.VolatilidadeAbstractThis study aimed to simulate the maximum acceptable loss for the risk of investing in a major agricultural commodities in Brazil, wheat. To fulfillthis objective, the study used the modeling of time series with autoregressive processes moving average (ARMA), conditional heteroskedasticity(GARCH) and value at risk (V@R), applied on a historical series of asset prices in a ten year period. The investigation database was collectedin the site CEPEA/ESALQ/USP and the motivation for choosing this historical series was due to the productive and economic importance of theState of Paran? throughout Brazil, the largest producer and commodity trader. The results discussed in this paper show that a level of statisticalsignificance of 1$ 228.40 under the investment and 5% R$174.19. Overall, these data suggest that every tonneof wheat sold, the producer can lose on your investment up to R$ 228.40. These and other information covered in the survey may provide supportstrategic tools for decision-making investment in commodities. The dynamics of prices expressed by the market volatility may reveal some activebehavior pattern, which can be useful for the formation of hedging policies, in which various producers assume the risk of the effected investment,thus minimizing the impact of the same on producers

Enhanced photocatalytic and antibacterial ability of Cu-doped anatase TiO2 thin films: theory and experiment.

Multifunctional thin films which can display both photocatalytic and antibacterial activity are of great interest industrially. Here, for the first time, we have used aerosol assisted chemical vapour deposition (AACVD) to deposit highly photoactive thin films of Cu-doped anatase TiO2 on glass substrates. The films displayed much enhanced photocatalytic activity relative to pure anatase, and showed excellent antibacterial (vs S.Aureus and E.Coli) ability. Using a combination of transient absorption spectroscopy (TAS), photoluminescence (PL) measurements and hybrid density functional theory calculations, we have gained nanoscopic insights into the improved properties of the Cu-doped TiO2 films. Our analysis has highlighted that the interactions between substitutional and interstitial Cu in the anatase lattice can explain the extended exciton lifetimes observed in the doped samples, and the enhanced UV/visible light photoactivities observed

Deeper Understanding of Interstitial Boron-Doped Anatase Thin Films as A Multifunctional Layer Through Theory and Experiment

Thin films of interstitial boron-doped anatase TiO2, with varying B concentrations, were deposited via one-step atmospheric pressure chemical vapor deposition (APCVD) on float glass substrates. The doped films showed a remarkable morphology and enhanced photoactivity when compared to their undoped analogues. The TiO2:B films also presented enhanced conductivity and electron mobility as measured by a Hall effect probe as well as a high adherence to the substrate, stability and extended lifetime. The structure and composition of the different samples of TiO2:B films were studied by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and dynamic secondary ion mass spectrometry (D-SIMS). Hybrid density functional theory was used to explore the defect chemistry of B-doped anatase and to understand the experimental results

Consilient Discrepancy: Porosity and Atmosphere in Cinema and Architecture

Cinema constitutes a way of looking at the world, at a world – its aspect, its appearance; but it also presents how that world looks, its prospect – by the prospective glance it throws back toward us. The “look” of a film – its mood, ambiance or atmosphere – eclipses formal and aesthetics registers. It is fundamentally world-forming, and therefore both cosmogonic and ethical: cosmogonic because it produces a world in the midst of, and as, the temporality that devolves through its passage; and ethical because the world it brings about is an inhabited world, a conjugation of people and place that constructs particular ways of being-there-together. The premise here is that atmosphere, ambiance and mood have never been vague categories for cinema and need not be for architecture: rather, that they are in fact producible through deliberate organizational strategies – kinematic and narrative in film, tectonic and material in architecture – according to what might be called “consilient discrepancy” – the coexistence of disseveral systems in unaligned multiplicity that, while never fusing, resonate to produce emergent conditions. Cinema offers architecture an accessible and instructive instance of such consilient discrepancy, because, in it, atmosphere is more fully captured and the conditions that create it more evidently analyzable. To that extent, cinema provides architecture with comparative grounds for engaging with atmosphere through a properly tectonic practice that can potentially enrich the design and experience of architecture. Consilient discrepancy is evident across multiple registers in film. It can function at the level of narrative, space and time and thus puts into question verisimilitude, causality, situational and durational veracity. An example of this is the constitutive disjunctions of Jean-Luc Godard’s jump cut montage where sampled film sequences, film and photographic stills, texts and citations, ambient sound, spoken word and music, build into complex assemblages of sense (Histoire(s) du Cinema, 1998). It is evident in Nicholas Roeg’s multiple, simultaneous temporalities where past and future events interpenetrate and mutually condition the narrative present (Bad Timing, 1980). Similarly, we can find it in Michelangelo Antonioni’s sequence shots that traverse multiple timeframes across the same space – a technique that enables past and present to communicate and amplify the affective, foundational value of the unseen and off-frame (The Passenger, 1975). Another example would be David Lynch’s labyrinthine existential settings, constituted of interminable slippages between indeterminable and infinitely potentialized spaces of dreams, imagination, memory and reality (Mulholland Drive, 2001). Likewise, we could cite Michael Hanake’s persistent displacement of causality and verisimilitude through ambiguous narrative viewpoints (Caché, 2005), and Roy Andersson’s radically liminal settings and characters whose lives constitute larval pre- and/or posthuman states of existence (A Pigeon Sat on a Branch Reflecting on Existence, 2014). This paper will foreground two foundational characteristics of atmosphere in cinema, as evident in the works just cited, and explore their applicability to architecture. The first characteristic is the consilient discrepancy outlined here by way of introduction, and the second, related characteristic, is a spatiality of porosity and occlusion. The provisional aim of comparing cinema and architecture according to this tectonic logic is to go beyond typical ways of understanding cinema’s formal engagement with architecture. For this purpose, a detailed analysis of Béla Tarr’s film Werckmeister Harmonies (2000) will serve as a case study for how the medium of cinema generates atmosphere, ambiance and mood through visual language. This will be followed by a similarly detailed consideration of concomitant qualities created in two recent works by the architects Flores Prats, the Mills Museum and Casal Balaguer. Functioning as exemplars of how cinematic qualities can be made manifest in architecture, these precedents will further substantiate the cinematic–architectonic proposition ventured in this paper

Agronomic Management of Indigenous Mycorrhizas

Many of the advantages conferred to plants by arbuscular mycorrhiza (AM) are associated to the ability of AM plants to explore a greater volume of soil through the extraradical mycelium. Sieverding (1991) estimates that for each centimetre of colonized root there is an increase of 15 cm3 on the volume of soil explored, this value can increase to 200 cm3 depending on the circumstances. Due to the enhancement of the volume of soil explored and the ability of the extraradical mycelium to absorb and translocate nutrients to the plant, one of the most obvious and important advantages resulting from mycorrhization is the uptake of nutrients. Among of which the ones that have immobilized forms in soil, such as P, assume particular significance. Besides this, many other benefits are recognized for AM plants (Gupta et al, 2000): water stress alleviation (Augé, 2004; Cho et al, 2006), protection from root pathogens (Graham, 2001), tolerance to toxic heavy metals and phytoremediation (Audet and Charest, 2006; Göhre and Paszkowski, 2006), tolerance to adverse conditions such as very high or low temperature, high salinity (Sannazzaro et al, 2006), high or low pH (Yano and Takaki, 2005) or better performance during transplantation shock (Subhan et al, 1998). The extraradical hyphae also stabilize soil aggregates by both enmeshing soil particles (Miller e Jastrow, 1992) and producing a glycoprotein, golmalin, which may act as a glue-like substance to adhere soil particles together (Wright and Upadhyaya, 1998). Despite the ubiquous distribution of mycorrhizal fungi (Smith and Read, 2000) and only a relative specificity between host plants and fungal isolates (McGonigle and Fitter, 1990), the obligate nature of the symbiosis implies the establishment of a plant propagation system, either under greenhouse conditions or in vitro laboratory propagation. These techniques result in high inoculum production costs, which still remains a serious problem since they are not competitive with production costs of phosphorus fertilizer. Even if farmers understand the significance of sustainable agricultural systems, the reduction of phosphorus inputs by using AM fungal inocula alone cannot be justified except, perhaps, in the case of high value crops (Saioto and Marumoto, 2002). Nurseries, high income horticulture farmers and no-agricultural application such as rehabilitation of degraded or devegetated landscapes are examples of areas where the use of commercial inoculum is current. Another serious problem is quality of commercial available products concerning guarantee of phatogene free content, storage conditions, most effective application methods and what types to use. Besides the information provided by suppliers about its inoculum can be deceiving, as from the usually referred total counts, only a fraction may be effective for a particular plant or in specific soil conditions. Gianinazzi and Vosátka (2004) assume that progress should be made towards registration procedures that stimulate the development of the mycorrhizal industry. Some on-farm inoculum production and application methods have been studied, allowing farmers to produce locally adapted isolates and generate a taxonomically diverse inoculum (Mohandas et al, 2004; Douds et al, 2005). However the inocula produced this way are not readily processed for mechanical application to the fields, being an obstacle to the utilization in large scale agriculture, especially row crops, moreover it would represent an additional mechanical operation with the corresponding economic and soil compaction costs. It is well recognized that inoculation of AM fungi has a potential significance in not only sustainable crop production, but also environmental conservation. However, the status quo of inoculation is far from practical technology that can be widely used in the field. Together a further basic understanding of the biology and diversity of AM fungi is needed (Abbott at al, 1995; Saito and Marumoto, 2002). Advances in ecology during the past decade have led to a much more detailed understanding of the potential negative consequences of species introductions and the potential for negative ecological consequences of invasions by mycorrhizal fungi is poorly understood. Schwartz et al, (2006) recommend that a careful assessment documenting the need for inoculation, and the likelihood of success, should be conducted prior to inoculation because inoculations are not universally beneficial. Agricultural practices such as crop rotation, tillage, weed control and fertilizer apllication all produce changes in the chemical, physical and biological soil variables and affect the ecological niches available for occupancy by the soil biota, influencing in different ways the symbiosis performance and consequently the inoculum development, shaping changes and upset balance of native populations. The molecular biology tools developed in the latest years have been very important for our perception of these changes, ensuing awareness of management choice implications in AM development. In this context, for extensive farming systems and regarding environmental and economic costs, the identification of agronomic management practices that allow controlled manipulation of the fungal community and capitalization of AM mutualistic effect making use of local inoculum, seem to be a wise option for mycorrhiza promotion and development of sustainable crop production

A hard x-ray photoemission study of transparent conducting fluorine-doped tin dioxide

Fluorine-doped tin oxide (FTO) is a commercially successful transparent conducting oxide with very good electrical (resistivities < 1×103 Ω·cm) and optical properties (transmittance > 85%). These properties coupled with cheap and large-scale deposition on float-glass lines means FTO has found commercial use in, for example, low emissivity windows and solar cells. However, despite its widespread application, a detailed understanding is lacking of the doping and defects in FTO. Recent work [1] has suggested that the fluorine interstitial plays a major role in limiting the conductivity of FTO. Here we present synchrotron radiation high energy x-ray photoemission spectroscopy (XPS) of the fluorine 1s core level of FTO films without in situ surface preparation. This probes deeper than standard XPS and shows that the fluorine interstitial is present not just at the surface of the films and is not an artefact of argon ion sputtering for surface preparation

Self-Compensation in Transparent Conducting F-Doped SnO2

The factors limiting the conductivity of fluorine-doped tin dioxide (FTO) produced via atmospheric pressure chemical vapor deposition are investigated. Modeling of the transport properties indicates that the measured Hall effect mobilities are far below the theoretical ionized impurity scattering limit. Significant compensation of donors by acceptors is present with a compensation ratio of 0.5, indicating that for every two donors there is approximately one acceptor. Hybrid density functional theory calculations of defect and impurity formation energies indicate the most probable acceptor-type defects. The fluorine interstitial defect has the lowest formation energy in the degenerate regime of FTO. Fluorine interstitials act as singly charged acceptors at the high Fermi levels corresponding to degenerately n-type films. X-ray photoemission spectroscopy of the fluorine impurities is consistent with the presence of substitutional F O donors and interstitial F i in a roughly 2:1 ratio in agreement with the compensation ratio indicated by the transport modeling. Quantitative analysis through Hall effect, X-ray photoemission spectroscopy, and calibrated secondary ion mass spectrometry further supports the presence of compensating fluorine-related defects

Genetic analysis of the interaction between Allium species and arbuscular mycorrhizal fungi

The response of Alliumcepa, A. roylei, A. fistulosum, and the hybrid A. fistulosum × A. roylei to the arbuscular mycorrhizal fungus (AMF) Glomus intraradices was studied. The genetic basis for response to AMF was analyzed in a tri-hybrid A. cepa × (A. roylei × A. fistulosum) population. Plant response to mycorrhizal symbiosis was expressed as relative mycorrhizal responsiveness (R′) and absolute responsiveness (R). In addition, the average performance (AP) of genotypes under mycorrhizal and non-mycorrhizal conditions was determined. Experiments were executed in 2 years, and comprised clonally propagated plants of each genotype grown in sterile soil, inoculated with G. intraradices or non-inoculated. Results were significantly correlated between both years. Biomass of non-mycorrhizal and mycorrhizal plants was significantly positively correlated. R′ was negatively correlated with biomass of non-mycorrhizal plants and hence unsuitable as a breeding criterion. R and AP were positively correlated with biomass of mycorrhizal and non-mycorrhizal plants. QTLs contributing to mycorrhizal response were located on a linkage map of the A. roylei × A. fistulosum parental genotype. Two QTLs from A. roylei were detected on chromosomes 2 and 3 for R, AP, and biomass of mycorrhizal plants. A QTL from A. fistulosum was detected on linkage group 9 for AP (but not R), biomass of mycorrhizal and non-mycorrhizal plants, and the number of stem-borne roots. Co-segregating QTLs for plant biomass, R and AP indicate that selection for plant biomass also selects for enhanced R and AP. Moreover, our findings suggest that modern onion breeding did not select against the response to AMF, as was suggested before for other cultivated species. Positive correlation between high number of roots, biomass and large response to AMF in close relatives of onion opens prospects to combine these traits for the development of more robust onion cultivars

A Global Fireball Observatory

The world's meteorite collections contain a very rich picture of what the early Solar System would have been made of, however the lack of spatial context with respect to their parent population for these samples is an issue. The asteroid population is equally as rich in surface mineralogies, and mapping these two populations (meteorites and asteroids) together is a major challenge for planetary science. Directly probing asteroids achieves this at a high cost. Observing meteorite falls and calculating their pre-atmospheric orbit on the other hand, is a cheaper way to approach the problem. The Global Fireball Observatory (GFO) collaboration was established in 2017 and brings together multiple institutions (from Australia, USA, Canada, Morocco, Saudi Arabia, the UK, and Argentina) to maximise the area for fireball observation time and therefore meteorite recoveries. The members have a choice to operate independently, but they can also choose to work in a fully collaborative manner with other GFO partners. This efficient approach leverages the experience gained from the Desert Fireball Network (DFN) pathfinder project in Australia. The state-of-the art technology (DFN camera systems and data reduction) and experience of the support teams is shared between all partners, freeing up time for science investigations and meteorite searching. With all networks combined together, the GFO collaboration already covers 0.6% of the Earth's surface for meteorite recovery as of mid-2019, and aims to reach 2% in the early 2020s. We estimate that after 5 years of operation, the GFO will have observed a fireball from virtually every meteorite type. This combined effort will bring new, fresh, extra-terrestrial material to the labs, yielding new insights about the formation of the Solar System.Comment: Accepted in PSS. 19 pages, 9 figure